DISINFACTS | Special edition 2023

Bio-based CO2 Biodegradable CO2 equivalents Carbon footprint Example: Fibres of nonwoven cloths KNOWLEDGE Are things in the green? Sustainability: The most important terms Sustainability is on everyone's lips. But the related vocabulary is not always immediately understandable in detail. So that you are still able to see the wood for the trees and join in the conversation about sustainability, we have compiled the most important terms for you. The material has been produced from renewable raw materials such as maize starch, vegetable cellulose, or lactic acid. Since further processing also plays a role, bio-based materials are not necessarily biodegradable and therefore should not be disposed of blanketly in the organic waste bin. Bio-based materials are not made from fossil raw materials, but depending on how they are produced, they can still have a large ecological footprint [1]. Biodegradable materials are naturally converted into biomass by microorganisms such as fungi or bacteria, releasing CO2, water, minerals, and possibly methane. The process may take several years. Therefore, biodegradable materials should not be disposed of in the organic waste bin or on the compost heap [1]. Note: Plastics from fossil resources can also be biodegradable. Bio-based and biodegradable therefore do not necessarily go hand in hand. Although carbon dioxide (CO2) makes up only a very small part of the Earth’s atmosphere (approx 0.04%), it has a major impact on global warming. This is because it absorbs heat and reflects it back to Earth instead of releasing it into space [2]. Processes or production steps frequently release not only CO2, but also other greenhouse gases such as methane (CH4) or nitrous oxide (N2O). Since CO2 is most relevant for man-made climate change, the total amount of greenhouse gases released is often expressed as so-called CO2 equivalents (CO2e). In this context, CO2 serves as a reference gas into which the greenhouse effect of the other gases is converted [3]. The carbon footprint is the estimated emission of a product or its CO2 impact. The entire life cycle of the product is taken into account: from raw material extraction to production, storage, transport, and use to final disposal or recycling. The term indicates how much greenhouse gas is released in total and is often expressed in CO2 equivalents (CO2e) [4]. However, the carbon footprint should not be used as the only measure of sustainability. It is also crucial, for example, how much water a process or product consumes during production, use, and subsequent maintenance. MILK 1.100 g CO2 caused by 1 litre milk1 2.370 g CO2 caused by 1 litre petrol2 380 g CO2 caused by one flowpack Bacillol® Zero 10 biodegradable Cellulose acetate* lyocell modal viscose cotton silk wool synthetic fibre fossil fuels-based semi-synthetic fibre biobased regenerated fibre natural fibre not biodegradable Cellulose acetat* PET PA PP Abbreviations: PA Polyamide PET Polyethylene terephthalate PP Polypropylene * depending on the degree of chemical modification, cellulose acetate is biogradable or not